Nitrogen X-ray absorption in the local ISM
By Efrain Gatuzz
The interstellar medium (ISM) affects all X-ray observations and hence the importance of modeling accurately the X-ray spectral features produced for such an environment. In this paper, we present the first detailed analysis of the Nitrogen K-edge absorption using high-resolution XMM-Newton spectra of both Galactic and extragalactic sources. Using state of the art photoabsorption cross-sections for the multiple nitrogen ionic species, we model the X-ray absorption features identified in the observations. We measured column densities for the cold, warm and hot components of the ISM. We also have tested the effects in the ISM column densities when including a photoionized model, to account for absorption intrinsic to the sources. Such analysis points out the importance of modeling simultaneously multiple K-edge absorption regions in order to study the contribution from both, the local ISM and the intrinsic absorption.
Future X-ray observatories will benefit greatly from this atomic data benchmarking. We performed Athena simulations in order to show the outstanding capabilities of the instrument to perform a detailed analysis of the multiphase ISM X-ray absorption.